Structural integrity of {alpha}-helix H12 in translation initiation factor eIF5B is critical for 80S complex stability.

ABSTRACT: Translation initiation factor eIF5B promotes GTP-dependent ribosomal subunit joining in the final step of the translation initiation pathway. The protein resembles a chalice with the α-helix H12 forming the stem connecting the GTP-binding domain cup to the domain IV base. Helix H12 has been proposed to function as a rigid lever arm governing domain IV movements in response to nucleotide binding and as a molecular ruler fixing the distance between domain IV and the G domain of the factor. To investigate its function, helix H12 was lengthened or shortened by one or two turns. In addition, six consecutive residues in the helix were substituted by Gly to alter the helical rigidity. Whereas the mutations had minimal impacts on the factor's binding to the ribosome and its GTP binding and hydroly

SUBMITTER: Shin BS 

PROVIDER: S-EPMC3062179 | biostudies-literature | 2011 Apr

REPOSITORIES: biostudies-literature